Rhesus monkeys are made hemianopic by total removal of the striate cortex in one hemisphere using subpial suction under direct vision. After the animals recover from surgery, they are trained on a series of visuomotor tasks, and the activity of single neurons in posterror parietal cortex both ipsilateral and contralateral to the lesion is studied. An initial series of experiments has shown that the parietal association cortex receives some visual input in the absence of the striate cortex, but that this visual input is concentrated in a limited region of the posterior parietal cortex rather than spread diffusely as in the normal cortex. This indicates that both the extrageniculate and the geniculostriate visual systems project to the posterior parietal cortex but that the recipient areas are anatomically separate.